Field of the Invention
The present invention relates to a method for producing a nozzle for injectors of internal combustion engines.
More precisely, the invention relates to a method for producing a nozzle for injectors of internal combustion engines having a nozzle tip with an outer surface coated with a layer of material that is highly resistant to corrosion.
Description of Prior Art
EP-A-2679323 describes a method for producing a nozzle provided with a metal coating, comprising the steps of:
providing a hollow metal body, which comprises a nozzle tip and a side wall that surrounds the nozzle tip, forming a hollow space;
filling the hollow space with a powdered metal coating material;
inserting an array of metal bodies into a tube;
closing the tube and evacuating the air from within the tube; and
subjecting the tube to hot isostatic pressing (HIP) so that the powdered coating material forms a solid coating bonded to the nozzle tip.
Subsequently, the body with the nozzle tip covered by the coating material is subjected to a machining, during which the side wall and a portion of the coating material are removed, so as to leave a layer of coating around the nozzle tip.
This method requires the production of a hollow body with a central core and an outer wall that surrounds the central core so as to form an inner space, which is filled with the powdered coating material. The production of a hollow body of this type is complex and expensive. The method described in EP-A-2679323 also requires a precise coupling between the tube and the hollow bodies to ensure that the coated body is symmetrical about its central axis.